Lifting, lowering and hauling and especially in mine hoisting



R. BLAIR ,961,

LIFTING. LOWERING AND HAULINIG AND ESPECIALLY IN MINE noxs'rme Nov. 22,1960 3 Sheets-Sheet 1 Filed June 11. 1956 Nov. 22, 1960 R. BLAIR 2,

LIFTING, LOWERING AND HAULINIG AND ESPECIALLY IN MINE HOISTING FiledJune 11, 1956 5 Sheets-Sheet 2 Nov. 22, 1960 R. BLAIR 2,9

LIFTING. LOWERING AND HAULINIG AND ESPECIALLY m MINE HOISTING Filed June11, 1956 s Sheets-Sheet :5

50 MAI/V sup/ac Y REV.

o o-I United States Patent LIFTING, LOWERING AND HAULING AND ESPECIALLYIN MINE HOISTING Robert Blair, 43 Main St., Johannesburg, Union of SouthAfrica Filed June 11, 1956, Ser. No. 590,731

Claims priority, application Union of South Africa June 12, 1955 4Claims. (Cl. 254-172) This invention relates to installations in whichlong lengths of a flexible element such as a rope or cable (referred toherein as a rope) are payed out or wound in at slow speed during theoperation of the installation. The primary application of the inventionis to mine hoisting and especially to the lowering and raising of stagesduring shaft-sinking; but the invention is not restricted to such uses.

The usual method of winding the rope in multiple layers on to the drumof a winch has disadvantages, the most significant of which is evidentwhen the rope has to be wound on to the drum under high tension, for itwill be appreciated that, when dealing with ropes which may be of theorder of 20,000 feet or more in length tensioned to the order of sometons, binding and nipping of the coils in adjacent layers is apt tooccur. Furthermore, it is obviously necessary when the rope is deliveredfrom the factory to wind it on to the drum under the required tension,an operation which is not without its inconveniences; and the drumitself and the structure associated with it must be massive enough towithstand the forces imposed on them and must consequently be costly.

The primary object of the present invention is to provide equipmentwhich avoids or minimizes the difiiculties of known procedure.

According to the invention, the equipment consists in a driven wheelaround which the rope passes in driving engagement with the wheel, awinch drum on which the rope is wound, a motor to drive the winch at aspeed that ensures a rate of pay'in and pay-out at all times exceedingthat of the wheel when the winch is in motion, means to form a loop inthe rope between the wheel and the winch, and means to maintain thelength of the loop between predctermined limits while keeping thetension in the rope of the loop substantially constant.

Further according to the invention, the loop-forming means consists in ajockey pulley suspended freely from the rope, and the means to maintainthe loop within its prescribed limits of length are control switcheslocated to be actuated by the pulley (or by structure associatedtherewith), when the loop attains the limits of its prescribed range oflengths, the switches controlling the motor that drives the winch.

In the operation of the equipment the wheel acts to divide the rope intoa zone of high-tension (between it and the load) and a zone oflow-tension (between it and the winch). The tensional differentialbetween the zones depends upon the nature of the wheel, the co-efiicientof friction between the rope and the wheel and the angle of contactbetween the rope and the wheel, and can be selected if not theoreticallythen empirically so to limit the tension in the low zone that themulti-layer wrapping of the rope around the winch drum is notdisadvantageous. Also, since the winch is in the low-tension zone itneed not have the robustness of a winch handling highly tensioned rope,its function being merely to pay-out rope as it is demanded by the wheeland wind it in as the wheel surrenders it.

A further aspect of considerable importance is that the tension in thelow zone can be so selected that the rope can be wound on to the winchdrum under the selected tension at the rope factory, thereby avoidingtroublesome and costly rewinding at the place of use.

Thus far the case of a single rope has been discussed. it will beappreciated however, that the invention is equally applicable to aplurality of ropes which are to be synchronously operated, such asoccurs in shaft-sinking when stages have to be supported. In fact, aswill be shown later, the invention has at least one advantage in theseinstallations which is not present in single-rope installations. Inmulti-rope installations the wheel is made to receive all the ropes, orseveral wheels may be gauged, in which case all, or all but one of thewheels, may be provided with clutches; or each wheel may have its ownwinch and motor.

An embodiment of the invention is illustrated in the accompanyingdrawings, in which Figure l is a perspective view of hoisting equipmentmade in accordance with the invention;

Figure 2 is a vertical section through the centre of Figure 1;

Figure 3 is a fragmentary view of a safety braking system, in elevation;and

Fig. 4 is a schematic diagram of the electrical circuit.

The equipment is shown as handling two ropes 10, 11, but it will beapparent that it could equally well be constructed to deal with fewer ormore than two ropes, depending on the nature of the duty which the hoistis to perform.

Each rope 10 or 11 is fed from a winch drum 12 or 13, round adirection-changing pulley 14 or 15, down into the cavity 16 of acompensating tower 17, round a jockey pulley 18 or 19, upwardly towardsand over a second direction-changing pulley 20 or 21, round a drivingwheel 22 or 23 and so away to the point of application of the load.

The operations of paying-out and winding-in the ropes are performed bythe driving wheels 22, 23. To this end the wheels are driven throughsuitable drive-transmitting mechanism such as a pinion 24 which mesheswith a gearwheel 25 keyed to the shaft 26 of one wheel, and rotated by amotor 26a, the drive to the second wheel being transmitted from thefirst wheel through a clutch (not shown).

To ensure that there is no significant slip between the ropes and thedriving wheel, the ropes are lapped several times around the wheels.

Within the tower 17 the ropes are constrained to form loops 27 and 28 bythe weight of the jockeys 18 and 19 and the structure associatedtherewith, which weight may be adjustably varied. These jockeys areguided for vertical movement within the cavity of the tower by pairs ofvertical rails 29, 3t) and 31, 32 which areengaged by rollers 33, 34mounted on the sheaves 35, 36 of the jockeys.

The lengths of the loops 27 and 28 vary as the jockeys 18 and 19 moveupwardly or downwardly in the tower 17.

The driving wheels 22, 23 divide the ropes into two zones, one, which isthat between the wheels and the load being a zone of high tension, themagnitude of which is governed by the load, and the other of which liesbetween the Wheels 22, 23 and the winch drums 12, 13

and which is a zone of low tension. The magnitude of.

the rope tension in the low-tension zone is governed by the weights ofthe jockeys 13, 19 and remains substantially constant as long as thejockeys are freely suspended from the loops 27, 28, irrespective of themagnitude, or variations in the magnitude, of the rope tension in thehigh-tension zone.

If the rates of pay-out and wind-in of one rope are always the same asthose of the other rope, the winch drums 12, 13 may be driven by asingle motor 51 housed in a suitable covering 50 with perhaps a clutchon one or either drum to'correct loss of synchronism, but if, as isassumed not to be the case-in the equipment being described, therates'may vary, then each drum is driven by its own motor.

The drive to the drums 12, 13 or each of them is so designed that thedrum is rotated at a rate that ensures that the wind-in or pay-out ofthe drum will at all times exceed that of the driving wheels 22, 23.

It follows that when the motor or motors 51 is or are running, the loopof rope 28 or 29 in the compensating tower 17 appropriate 'to'that'motor is always on the increase while rope is being payed out by thewinch 12 or 13, and onthe decrease while it is being wound in. Itfollows too that themeans'that ke'epsthe length of the loop 27 or 28;within its prescribed range must be one that arress'tn'e fotatiori' of-the winch drum 12 or 13 when the limits of'the range are reached. Inthe embodiment being described the means consist in two control switches39, 40 located to be actuated by contact with the chassis 37 or38 onwhich the jockey pulley 18 or 19 is mounted, whenever the pulley reachesits upper and its lower limits, the switches being comprised in thecircuit of the drum motor or operating a clutch between the motor andthe Winch drum.

When the rope is being payed out and the length of the rope in the loop27 or 28 is increasing, actuation of the lower switch 40 immobilizes thewinch drive whereupon continued lowering of the load on the rope causesthe loop to shorten, until the jockey reaches its upper limit andremobili zes the motor. A further quota of rope is then payed out; andso on.

l When a rope is being wound in, the reversal of the drive to thedriving wheel 22 or 23 is arranged also to reverse the winch drive andthe control switches 39, 44?, so that the reverse operation occurs, thewinch drum being stopped when the jockey pulley reaches its upper limitand being started when it reaches its lower limit.

The embodiment may also comprise certain safety devices which come intooperation in case of need. These may include limit switches 41, 42beyond the control switches 39, 40, which, should the jockey pulley 18or 19 fail to actuate the control switches 39, 40 or the latter notfunction, immobilize the entire system. There may also be included abraking device on, associated with, or actuated by, the jockey pulley 18 or 19. This device may consist (Fig. 3) in a pair of brake shoes 43,44 irirespect of each jockey 18 or 19. Each pair of brake shoes 43, 44is carried on bell cranks 45, 46, pivotally mounted on a horizontalmember 47 of the framework of the tower 17 At rest, the shoes are closeto but free from the periphcr es of the pulleys 15, 21, which may bethickened to provide braking surfaces. The spacing of the shoes from thepulleys is adjustable by screws 48, 49 that make contact with the bellcranks 45, 46.

In use, when the jockey 19 moves above its permitted range, it makescontact with the shoes 43; 44 and jams them between itself and thepulleys 15, 21. The train of pulleys is thus immobilized, with the ropeskinked around them soto resist further paying out of the ropes that theropes slip on the driving wheels 22, 23.

The brake device has also a valuable function in a multiple ropeinstallation where one of the ropes breaks. In these circumstances thejockey pulley associated with the broken rope actuates the lower limitswitch 41 to bring the system to a stop.

' In Fig. 4, which is a circuit diagram, M1 and M2 representrespectively the motors that drive the winch 12 or 13 and the drivenwheel 22, 23.

There are in fact two motors that drive the winches 12, 13,0ne for each,but for ease of description, only one and its control means areillustrated and described. The second is merely a duplication of thefirst.

M1 is fed from a mains supply 50 through a reversing contactor 52. M2 isfed from the mains supply 50 through a circuit breaker 54.

The upper and lower control switches 39, 40 operate to start and stopthe motor M1 through the reversing contactor 52. I

Assuming a forward wind of the driven wheels 22, 23 (that is the load isbeing lowered) the jockey 18 travels upwardly until it comes intocontact with the top control switch 39 and closes it to operate themotor circuit 59, 52. This circuit is operated by the control circuit58, 39, 40, directional switch 56, 41, which is closed by the closing ofthe control switch 39.

Motor M1 is set in motion and pays out rope, allowing the jockey 18 tomove downwards. On reaching the bottom control switch 40, it opens theswitch to open the control circuit, which in turn opens the motorcircuit to stop the motor M1. The jockey then moves upwardly, to closeswitch 39, to restart the motor, and so on.

On reverse wind (i.e.vthe load ascending) the jockey moves downwardlyuntil it reaches the bottom control switch 40, thereby closing circuit58, 42, 39, 40, 56, which in turn operates motor circuit 50, 5-2 tostart the motor. Rope is now wound on to the winch drum and lifts thejockey, which ascends to open the top control switch 39 and stop themotor M1. The jockey descends, and so on.

In the event of the control switches failing to operate, the limitswitches 42, 41, situated respectively at the top and bottom of thetower 17 are operated by the jockey to open the control circuit andthereby to open the motor circuit to prevent overor underwind.

I claim:

1. Lifting, lowering or hauling equipment comprising a rope, a drivenwheel around which the rope passes in driving engagement with the wheel,a motor to drive said wheel, a winch drum on which the rope is wound, aload to which the end of said rope remote from said winch is attached, amotor to drive the winch at a speed that ensures a rate of pay-in andpay-out at all times exceeding that of the wheel when the winch is inmotion, a tower located between the wheel and the winch, pulleysarranged to lead the rope into and out of the tower, a jockey pulleyfreely suspended from the rope within the tower to form a loop of ropebetween the pulleys, which loop is contained within the tower, switcheslocated to be actuated by structure associated with the jockey pulley,when the loop attains the limits of its prescribed range of lengths,said switches controlling the motor that drives the winch; limitswitches beyond said switches arranged to be operated by structureassociated with the jockey pulley to stop said driven wheel and winchmotors when the loop length moves out of the prescribed range; andbraking means to lock the equipment if the length of the loop moves outof the prescribed range, consisting in shoes that are arranged to bejammed between the jockey pulley and pulleys due to shortening of theloop.

2. Lifting, lowering or hauling equipment comprising a rope, a drivenwheel around which the rope passes in driving engagement with the wheel,a motor to drive said wheel, a winch drum on which the rope is wound, aload to which the end of said rope remote from said winch is attached, amotor to drive the winch at a speed that ensures a rate of pay-in andpay-out at all times exceeding that of the wheel when the winch is inmotion, pulleys including a jockey pulley to form a loop in the ropebetween the wheel and the winch, and means to maintain the length of theloop between predetermined limits while keeping the tension in the ropeof the loop substantially constant; and including also braking means tolock the equipment if the length of the loop moves out of the prescribedrange.

3.' Equipment as claimed in claim 2 in which the braking means comprisesshoes that are arranged to be between the jockey pulley and pulleys dueto shortening of the loop.

4. Lifting, lowering or hauling equipment comprising a rope, a drivenwheel around which the rope passes in driving engagement with the wheel,a motor to drive said Wheel, a winch drum on which the rope is wound, aload to which the end of said rope remote from said winch is attached, amotor to drive the winch at a speed that ensures a rate of pay-in andpay-out at all times exceeding that of the wheel when the winch is inmotion, a tower located between the wheel and the winch, pulleysarranged to lead the rope into and out of the tower, a jockey pulleyfreely suspended from the rope within the tower to form a loop of ropebetween the pulleys, which loop is contained within the tower, controlswitches located to be actuated by structure associated with the jockeypulley, when the loop attains the limits of its prescribed range oflengths, the switches controlling the motor that drives the winch; limitswitches beyond the control switches arranged to be operated bystructure associated with the jockey pulley to stop said driven wheeland winch motors when the loop length moves out of the prescribed range;and braking means to lock the equipment if the length of the loop movesout of the prescribed range, consisting in shoes that are arranged to bejammed between the jockey pulley and pulleys due to shortening of theloop.

References Cited in the file of this patent UNITED STATES PATENTS1,475,855 Murdock Nov. 27, 1923 1,832,430 Siebs Nov. 17, 1931 2,203,946Doescher June 11, 1940 2,603,428 Newcombe July 15, 1952 2,741,437Haworth Apr. 10, 1956 2,825,512 Andren Mar. 4, 1958 FOREIGN PATENTS463,216 Italy Apr. 20, 1951

